The play will be held through the Roundabout Theatre Company, and begin previews on Oct. 1, 2015 for an Oct. 29 opening. Even better, Thérèse Raquin is the first play announced for the 2015-2016 season, and it definitely sounds like a big get: It was written by playweight Helen Edmundson, and is based on the novel of the same name by Emile Zola. From EW:

Therese Raquin tells the love and lust-filled story of an unhappily married woman whose complacent, loveless union to her sickly cousin is flipped by the arrival of a passionate lover.

Knightley's role is the first announced so far, but considering how flawless her performance in 2012's beautiful Anna Karenina — which was basically filmed as if it were being performed on stage — was, I have no doubt the show will still be amazing no matter who she's cast with.